On Wed, Feb 25, 2015 at 10:43 AM, Ionel Cristian Mărieș <contact@ionelmc.ro> wrote:
I think exceptions are great candidates to have an __eq__ method - they already have a __hash__ (that's computed from the contained values) and they are already containers in a way (they all have the `args` attribute).
Are you sure their hashes are computed from contained values? I just tried it, generated two exceptions that should be indistinguishable, and they had different hashes: rosuav@sikorsky:~$ python3 Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07) [GCC 4.7.2] on linux Type "help", "copyright", "credits" or "license" for more information.
try: open("/root/asdf") ... except OSError as e: e1=e ... try: open("/root/asdf") ... except OSError as e: e2=e ... hash(e1) -9223363249876220580 hash(e2) -9223363249876220572 type(e1).__hash__ <slot wrapper '__hash__' of 'object' objects>
I suspect the last line implies that there's no __hash__ defined anywhere in the exception hierarchy, and it's using the default hash implementation from object(). In any case, those two exceptions appear to have different hashes, and they have the same args and filename. ChrisA